deftools.io Math & Data

Sales Tax & VAT Calculator

Add or remove sales tax and VAT from any amount. Find the price before tax, the tax amount, and the final price with tax for any tax rate.

+ Second tax layer (state + local, QST, etc.) (optional)

Compound = rate 2 applies to the amount after rate 1 (e.g. Quebec QST on top of GST). Separate = rate 2 applies to the same base as rate 1 (e.g. US state + local). The total tax is the sum.

About this tool

Sales Tax & VAT Calculator adds or removes sales tax and VAT from any amount. Type a price and a tax rate, then read off the tax amount and the final price. Two modes cover the two questions people actually ask: "how much does this cost with tax?" (net → gross) and "what was the price before tax was added?" (gross → net).

Example 1 — add 20% VAT to a €100.00 net price → tax €20.00, gross €120.00. Example 2 — a price tag reads £60.00 including 20% VAT → net £50.00, tax £10.00. The effective-rate box shows the combined rate so you can sanity-check multi-layer setups (e.g. US state + local sales tax, or Canadian GST + QST).

The optional second tax layer handles compound taxes (Quebec charges QST on top of the GST-inclusive amount) and separate taxes (a US city adds its local rate to the same base as the state rate). Pick a country preset for common VAT/GST rates, or type any custom rate.

FAQ

How is the price before tax calculated?

To remove tax: net = gross ÷ (1 + rate/100). For a £60 price with 20% VAT: 60 ÷ 1.2 = £50 net, and £10 is the tax. To add tax: gross = net × (1 + rate/100). For €100 at 19%: 100 × 1.19 = €119 gross.

What is a VAT-inclusive vs VAT-exclusive price?

VAT-exclusive (net) is the price before tax — what a business quotes to another VAT-registered business. VAT-inclusive (gross) is what a consumer pays, with tax already in the sticker price. B2B prices in the EU are typically net; consumer prices are typically gross.

How does the second tax layer work?

"Compound" applies rate 2 to the amount after rate 1 has been added — Quebec does this (QST is charged on the GST-inclusive amount). "Separate" applies rate 2 to the same base amount as rate 1 — US state + local sales tax work this way. The total tax is the sum of both layers.

Does this handle US sales tax?

Yes. US sales tax is almost always quoted as already-included in the shelf price at the register, so use "Remove tax" only when you know the combined state + local rate. The presets list a few combined rates (California average, NYC, Tennessee); for other states enter your state + local rate as a second separate tax layer.

Why does the effective rate differ from the entered rate?

When two taxes compound, the effective rate is higher than the simple sum because rate 2 is charged on a larger base. For example 5% GST + 9.975% QST compounded gives an effective rate of about 15.5%, not 14.975% — that is correct and matches how Quebec actually calculates it.

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